This Mentored Patient-Oriented Research Career Development Award (K-23) application is to support Dr. Yen's development as an independent research scientist with a programmatic line of research that examines the phenomenology of suicidal behaviors. Dr. Yen seeks further training to apply her previous clinical and research experiences with adult borderline personality disorder (BPD) patients, to work with adolescents. BPD represents a significant risk factor for repeat suicide attempts and suicide deaths, yet there has been no prospective study of BPD among adolescent suicide attempters. The proposed study seeks to examine the associations between affective traits consistent with BPD, family functioning, and adolescent suicidality. To facilitate her career goals, Dr. Yen proposes a training plan which consists of: 1) mentorship and clinical supervision provided by a team of experts in adolescent suicidality, personality disorders, and prospective studies;2) completion of formal coursework, seminars, and workshops;3) participation in relevant, ongoing projects at Brown University Medical School;and 4) implementation of the proposed research project. This plan will enable her to increase her conceptual knowledge of adolescent development and psychopathology, obtain additional training in assessment and treatment of adolescents, and further develop her skills in research design and data analyses. Dr. Yen proposes to examine a model, heavily influenced by Linehan's biosocial theory of BPD and by prominent developmental theories, in which the combination of individual dispositional factors (affective processing consistent with BPD) and environmental factors (invalidating family environment) is hypothesized to predict adolescent suicidal behavior (ideation and attempts). A naturalistic, descriptive, 6-month follow-up study of 120 adolescents after being hospitalized for suicidal behavior will be implemented to examine this model. Weekly or monthly ratings on key predictor and outcome variables will be obtained via four assessments over the 6-month interval to allow for time-varying analyses. The proposed study would address a significant gap in knowledge, as it would be the first prospective study to examine BPD traits as well as the first study to examine key predictor variables dynamically, in suicidal adolescents.